God so loved the world that he gave his only Son, so that everyone who believes in him might not perish but might have eternal life.
Today, St. John speaks to us of God's infinite love. He loves us so much that He has sent His eternal Son to the World, and has revealed to us His own "family intimacy." Now we know that God is not a solitary being; He Himself is Three Persons: Father, Son and Holy Spirit.
— What a great and precious mystery! Three Persons in one only God. Because ... if He was not "Three," how could He be Love? (To love, you need at least "Another one".